Cellphone as Tracker: X Marks Your Doubts - New York Times

Timely reality check 

None of this entails anything exotic. The technology has been ready for a while, but not the customers. Prospective benefits have seemed paltry when placed against privacy concerns. Who will have access to our location information — present and past? Can carriers assure us that their systems are impervious to threats from stalkers and other malicious intruders or neglectful employees — or from government snoops without search warrants? Contemplating worst-case scenarios, our hands holding these very mobile devices have been frozen, hesitant to turn the location beacon on. Are we finally ready to flip the switch?

Source: Cellphone as Tracker: X Marks Your Doubts - New York Times